/*
 * Copyright 2011-2012 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.sabayframework.activity.impl;

import org.sabayframework.activity.ActivityContext;
import org.sabayframework.channel.Lock;

/**
 * Object activity is a stateful activity that processes one object per execution.
 * @author Alex Antonau  
 * */
public abstract class ObjectActivity<T> extends StatefulActivity<T, T> {

	private T data;
	@Override
	public void input(ActivityContext<T, T> ctx, Lock<T> inputLock) throws Exception {
		this.data = inputLock.get(0); 
	}

	@Override
	public void process(ActivityContext<T, T> ctx) throws Exception{
		data = process(data);
	}
	
	public abstract T process(T input)throws Exception;

	@Override
	public void output(ActivityContext<T, T> ctx, Lock<T> outputLock) throws Exception {
		outputLock.set(0, data);
	}

}
